講演情報
[PPS03-07]Elastic property of Ryugu samples: Preliminary summary★Invited Papers
*小野寺 圭祐1、猪 裕太2、田中 智3、川村 太一4、金丸 礼3、石崎 拓也3、深井 稜汰3、辻 健5、中村 智樹6、上椙 真之7、圦本 尚義8、野口 高明9、岡崎 隆司10、薮田 ひかる11、奈良岡 浩10、坂本 佳奈子3、橘 省吾5、渡邊 誠一郎12、津田 雄一3,5、はやぶさ2 初期サンプル分析チーム (1.東京大学地震研究所、2.関西学院大学、3.JAXA宇宙科学研究所、4.パリ地球物理研究所/パリシテ大学、5.東京大学、6.東北大学、7.公益財団法人高輝度光科学研究センター、8.北海道大学、9.京都大学、10.九州大学、11.広島大学、12.名古屋大学)
キーワード：
はやぶさ2、リュウグウ、弾性波速度、小惑星地震学
Elastic property is one of the most fundamental parameters to characterize planetary bodies. In the case of asteroids, elastic parameters such as rigidity and seismic wave velocity play an important role in explaining surface morphology, impact phenomena, and physical weathering (e.g., Arakawa et al., 2020; Cho et al., 2021; Honda et al., 2021; Takaki et al., 2022). Also, these parameters are crucial constraints for numerical studies of asteroid formation (e.g., Nakamura et al., 2022). Therefore, the measurement of elastic property is pivotal to deepen our understanding of both current phenomena as well as past evolution processes of asteroids.
In the framework of Hayabusa2 initial sample analysis, we measured the seismic wave velocity of the Ryugu particles labeled as C0002-No3 and C0002-No4, which were retrieved from the second touch-down site (i.e., near the artificially formed crater; Arakawa et al., 2020; Morota et al., 2020). Moreover, by combining the previously measured density value (Nakamura et al., 2022), we estimated Young’s modulus as well. While Nakamura et al. (2022) showed the averaged elastic parameters, we take a closer look at each sample and try to understand the variations among particles. Furthermore, in comparison with other carbonaceous chondrites, we investigate which type of meteorite shows similar elastic features to those of Ryugu samples.
In the presentation, we will show the seismic wave velocity and Young’s modulus of the returned Ryugu samples, and discuss how these parameters are different from other carbonaceous chondrites.
References
- Arakawa et al. (2020), Science, 368, 67.
- Cho et al. (2021), JGR: Planets, 126, e2020JE006572.
- Honda et al. (2021), Icarus, 366, 114530.
- Morota et al. (2020), Science, 368, 654.
- Nakamura et al. (2022), Science, 10.1126/science.abn8671.
- Takaki et al. (2022), Icarus, 377, 114911.
In the framework of Hayabusa2 initial sample analysis, we measured the seismic wave velocity of the Ryugu particles labeled as C0002-No3 and C0002-No4, which were retrieved from the second touch-down site (i.e., near the artificially formed crater; Arakawa et al., 2020; Morota et al., 2020). Moreover, by combining the previously measured density value (Nakamura et al., 2022), we estimated Young’s modulus as well. While Nakamura et al. (2022) showed the averaged elastic parameters, we take a closer look at each sample and try to understand the variations among particles. Furthermore, in comparison with other carbonaceous chondrites, we investigate which type of meteorite shows similar elastic features to those of Ryugu samples.
In the presentation, we will show the seismic wave velocity and Young’s modulus of the returned Ryugu samples, and discuss how these parameters are different from other carbonaceous chondrites.
References
- Arakawa et al. (2020), Science, 368, 67.
- Cho et al. (2021), JGR: Planets, 126, e2020JE006572.
- Honda et al. (2021), Icarus, 366, 114530.
- Morota et al. (2020), Science, 368, 654.
- Nakamura et al. (2022), Science, 10.1126/science.abn8671.
- Takaki et al. (2022), Icarus, 377, 114911.